1. Field of the Invention
The present invention relates to a heat-sensitive recording material having light resistance.
2. Description of the Related Art
Heat-sensitive recording has been recently developed because a recording device thereof is simple, reliability is high, and maintenance is unnecessary. As heat-sensitive recording materials, those utilizing a reaction of a diazonium salt compound with a coupler, those utilizing a reaction of an electron-donating colorless dye, an electron-accepting compound, and the like have been conventionally and widely known.
However, in case of heat-sensitive recording materials using a diazonium salt compound or an electron-donating colorless dye, texture is colored by a photo oxidation article which is generated by coexistence of oxygen during light irradiation, and it is one of factors of lowering quality. Accordingly, it has been investigated to reduce the coloring by imparting an undercoat layer for intercepting oxygen and by introducing the precursor layer of an ultraviolet absorbent, but its effect was not adequate.